The present invention relates to a subscriber unit such as a DSU (Digital Service Unit) used for a subscriber radio communication sytsem such as a WLL (Wireless Local Loop), and particularly to a device for setting internal parameters of the subscriber unit.
FIG. 2 is a schematic diagram illustrating a conventional system configuration of the subscriber radio communication system wherein subscribers exchange data with a base station by way of radio signals.
Referring to FIG. 2, there is equipped, at the subscriber side, a subscriber unit 22 having switches 26, such as dip-switches, and connected with a subscriber terminal 20, or a subscriber unit 23 connected to a console, such as a personal computer, together with a subscriber terminal 21.
At the base station side, there is provided a base unit 24, such as an OCU (Office Channel Unit) accommodated in a SLT (Subscriber Line Terminal) 25.
In the subscriber radio communication system, different data transmission modes are usually applied to data exchange between the base unit 24 and its upper unit, according to kinds of the subscriber terminals 20 and 21, that is, according to whether they are ordinary telephone terminals or digital terminals such as a facsimile terminal or a data modem. Therefore, the subscriber units 22 and 23 are to be designed to inform the base unit 24 of the kinds of the respective subscriber terminals 20 and 21 connected thereto, and, for that purpose, respective kinds of the subscriber terminals 20 and 21 are to be beforehand set in the internal parameters of the subscriber units 22 and 23, respectively.
For setting such internal parameters as above described, for example, the switches 26 or the console 27 has been provided to the subscriber unit 22 or 23.
In other words, the internal parameters of the subscriber units are set by manipulating switches provided therein, such as the switches 26 of the subscriber unit 22 of FIG. 2, or by manipulating consoles connected thereto, such as the console 27 connected to the subscriber unit 23 of FIG. 2, in the conventional subscriber radio communication system.
Besides the kind of subscriber terminal as above described, there are certain internal parameters which have been set in the subscriber unit 22 or 23 by way of the switches 26 or the console 27. An example of them concerns a number display service for displaying a number, a telephone number, for example, of the other subscriber terminal with which the subscriber terminal 20 or 21 is communicating.
In a standard proposed in a document entitled "Personal Handy Phone System ARIB Standard, version 2, RCR STD-28", by ARIB (Association of Radio Industries and Businesses), it is defined at page 336, concerning the above number display service, that whether the subscriber unit informs the base unit of the number of subscriber terminal or not can be selected optionally by the subscriber. Here, also, the internal parameter of the subscriber unit concerning whether the subscriber unit informs a receiver-side subscriber terminal of the number of the transmitter-side subscriber terminal or not should be set optionally according to subscriber's selection, and the parameter setting has been performed conventionally by way of the switches 26, for example, of the subscriber unit 22, or the console 27, for example, connected to the subscriber unit 23.
However, there are demerits as follows in these conventional methods of internal parameter setting, such as by manipulating the switches 26 of the subscriber unit 22 or by manipulating the console 27 connected to the subscriber unit 23.
In the method of parameter setting by manipulating the switches 26 of the subscriber unit 22, for example, the switches 26, which are designed to be manipulated easily, may be turned because of an unexpected shock received by the subscriber unit 22, or may be set unexpectedly by an incorrect manipulation. There is also a problem of cost. The switches 26 themselves increase the number of parts and, consequently, the production cost of the subscriber unit 22. Furthermore, the element number of the switches 26 and their usage are fixed when the subscriber unit 22 is designed. Therefore, it is very difficult to deal with new parameters which become necessary to be set after shipping of the subscriber unit 22.
On the other hand, in the method of parameter setting by way of the console 27, for example, the console 27 must be connected to the subscriber terminal 23 for performing the parameter setting. Therefore, troublesome effort is imposed to the subscriber for connecting the console 27 to the subscriber unit 23 each time when setting of the internal parameters of the subscriber unit 23 is to be changed, in addition to the necessity of preparing the console 27 even when it is not used but for the parameter setting.